Walk behind lawn mowers are known having a housing supported for movement over the ground by a plurality of wheels. A cutting blade rotates horizontally in a cutting chamber located within the housing. The user pushes or guides the mower by holding an upwardly extending handle assembly connected to the mower housing. The cutting blade cuts grass as the mower travels over the ground. The grass clippings are usually discharged through a side or rear discharge opening provided in the mower housing.
Mulching mowers are known in which the usual discharge opening from the housing is either blocked or is absent in the first place. The purpose of such mulching mowers is to use the grass clippings as mulch, i.e. to drive the grass clippings back downwardly into the cut grass path where they can decompose and serve as fertilizer. Some mulching mowers have used deflectors or kicker members contained on the underside of the mower housing in the cutting chamber. These deflectors were shaped to assist in the downward movement and disposal of the grass clippings. U.S. Pat. No. 4,205,512 to Thorud discloses a prior art mulching mower of this type.
Mulching mowers of the type known previously were not well suited for cutting large areas of grass. Such mowers were limited in width and used only a single cutting blade. For example, most mowers of this type did not exceed 21 inches in width. Thus, it would be too time consuming and labor intensive to use this type of mower for cutting large areas of grass such as those found on golf courses, parks, and the like.
Mowing machines are known which are specifically designed for cutting relatively large areas of the type just mentioned. These machines include a cutting deck attached to a traction unit that is normally self-propelled for carrying the cutting deck over the ground. The cutting deck is quite wide and includes more than one blade arranged across the width of the cutting deck to provide a wide swath of cut grass for each pass of the mowing machine. However, none of the previously known mowers of this type were effective mulchers.